1、大学英语四级模拟试卷 556及答案与解析 一、 Part I Writing (30 minutes) 1 For this part, you are allowed thirty minutes to write a composition on the topic Tourist Industry in China. You should write at least 120 words following the outline given below in Chinese: Tourist Industry in China 1. 旅游业的重要性 ; 2. 中国旅游业存在的问题 ;
2、3. 提出你解决问题的见解。 二、 Part II Reading Comprehension (Skimming and Scanning) (15 minutes) Directions: In this part, you will have 15 minutes to go over the passage quickly and answer the questions attached to the passage. For questions 1-7, mark： Y (for YES) if the statement agrees with the information g
3、iven in the passage; N (for NO) if the statement contradicts the information given in the passage; NG (for NOT GIVEN) if the information is not given in the passage. 1 Inside a small chamber at a Kent State University laboratory, hamsters sleep, eat, play and rest while fluid flows in and out of tub
4、es threaded through their tiny brains. It took biology professor J. Da vid Glass two years to set up the finicky dialysis system, which measures a key neurotransmitter in the biological clocks of these nocturnal rodents. His payoff came in 1996, when he became the first re searcher to measure seroto
5、nin levels rising and falling in the biological clock area of the brain during an animals daily cycle. Serotonin is the “feel good“ chemical manipulated by widely prescribed drugs such as Prozac. Meanwhile, in a larger chamber down the hall, Glass is monitoring tropical monkeys. He has found that ex
6、ercise and arousal from sleep have major impacts on the biological rhythms of the monkeys, permanently shifting their clocks in the absence of normal daylight and darkness cues. Glasss research and that of others could have implications for the millions of people who take com monanti-depressants and
7、 other drugs that affect serotonin in the brain. It has long been known that the substance is a key player in the biological clock, and that the region has an unusually high concentration of receptors for the neurotransmitter. Glasss work is part of the fast-growing field of circadian(or daily)rhyth
8、m research focused on a region at the base of the brain, the size of a corn kernel, that scientists discovered 25 years ago is the bodys timing mechanism. Like other animals and even plants, humans have built-in clocks that regulate internal functions on a 24-hour basis. For most mammals, the clocks
9、 trigger sleep and waking, as well as metabolism, hor mone levels, body temperature and many other changes. This is a particularly exciting time for circadian-rhythm researchers. In recent times, scientists at universities in Illinois, Texas and Japan have found genes involved with the clock, includ
10、ing one that appears to be a basic building block of the mechanism and is common across all species, from fruit flies to humans. Meanwhile, researchers like Glass, whose work has attracted US $1.2 million(9.6 mil lion RMB)in grants from the National Institute of Health, are trying to understand how
11、the clock works. Sitting on top of the optic nerve, the clock is heavily influenced by light. But other factors, too, are involved in resetting the mechanism, most notably physical activity and substances like serotonin. Glass and his students found that, when lights in the hamster chamber were swit
12、ched off, the serotonin levels in the rodentsclock region shot up: hamsters are nocturnal, meaning they rest during the day and are awake at night. But when hamsters in the midst of their sleep cycle were put onto an activity wheel, a significant rise in serotonin levels was measured in those hamste
13、rs that woke up enough to ex ercise. It has long been known that serotonin is key to body clock function, according to Thomas Wehr, a scientist at the National Institute of Mental Health in Bethesda, Maryland. Researchers at the Mary land Institute took cells from the clock region of the brain, spri
14、nkled serotonin on them and, by monito ring electrical impulses, watched the cells “reset“ themselves. “There are certain drugs used with humans that have also been squirted on these cells in dishes and have been shown to reset the clock in the dish, so it seems quite possible there are similar effe
15、cts in hu mans who take these drugs. “Wehr says. Indeed, some people taking anti-depressants do report sleep disorders such as insomnia or daytime drowsiness that could be related to changes in their biological clocks. Human studies have yet to focus on the issue. Studies have found that serotonin a
16、ffects the clock in different ways, depending on the point in the cells daily cycle that it is administered. Glass recently completed an experiment using marmosets, small monkeys native to Central and South America. Researchers moved a sleeping marmoset to anoth er cage, then monitored it as it scur
17、ried around its new environment. After this burst of activity, the marmoset shifted its cycles forward or backward a few hours, and they remained shifted, apparently in definitely. Cycles were pushed back when the disruption occurred early in the sleep period; they shifted forward when the disruptio
18、n occurred late in the cycle. According to Glass, the experiment demonstrates what scientists have known anecdotally for a long time: that exercise, when performed at certain times, shifts our clocks. Exercise has long been recommended to speed recovery from jet lag, for example. That may be because
19、 exercise boosts serotonin. Glass found he could mimic the effect of the arousal experiment by injecting a serotonin like drug and believes the findings suggest something similar could be expected in people. “Were getting closer and closer to making the link that humans can adjust their circadian cl
20、ock through natural means such as exercise, “Glass says. 2 Prozac is the “feel good“ chemical manipulated by widely prescribed drugs. （ A） Y （ B） N （ C） NG 3 For most mammals, metabolism, hormone levels, body temperature and many other changes are not triggered by clocks. （ A） Y （ B） N （ C） NG 4 Lig
21、ht is one of the important factors that influence the clock. （ A） Y （ B） N （ C） NG 5 According to the passage, monkeys, like human beings are worried about the change of clocks that triggered the body nerve. （ A） Y （ B） N （ C） NG 6 Insomnia or daytime drowsiness that related biological clocks were n
22、ot focused on by human studies. （ A） Y （ B） N （ C） NG 7 When the disruption occured in the cycle, cycles were pushed back. （ A） Y （ B） N （ C） NG 8 The clock, however, can be affected by serotonin in different ways, depending on the point in the cells daily cycle. （ A） Y （ B） N （ C） NG 9 But when ham
23、sters in the midst of their sleep cycle were put onto an activity wheel, _. 10 Glass has found that _ have major impacts on the biological rhythms of the monkeys. 11 Exercise has long been recommended to _. Section A Directions: In this section, you will hear 8 short conversations and 2 long convers
24、ations. At the end of each conversation, one or more questions will be asked about what was said. Both the conversation and the questions will be spoken only once. After each question there will be a pause. During the pause, you must read the four choices marked A, B, C and D, and decide which is th
25、e best answer. （ A） The girls got on well with each other. （ B） Its understandable that girls dont get along. （ C） She was angry with the other young stars. （ D） The girls lacked the courage to fight. （ A） The woman does her own housework. （ B） The woman needs a housekeeper. （ C） The womans house is
26、 in a mess. （ D） The woman works as a housekeeper. （ A） The Edwards are quite well off. （ B） The Edwards should cut down on their living expenses. （ C） Itll be unwise for the Edwards to buy another house. （ D） Its too expensive for the Edwards to live in their present house. （ A） The woman didnt exp
27、ect it to be so warm at noon. （ B） The woman is sensitive to weather changes. （ C） The weather forecast is unreliable. （ D） The weather turned cold all of a sudden. （ A） At a clinic. （ B） In a supermarket. （ C） At a restaurant （ D） In an ice cream shop. （ A） The woman didnt feel any danger growing u
28、p in the Bronx. （ B） The man thinks it was quite safe living in the Bronx district. （ C） The woman started working at an early age to support her family. （ D） The man doesnt think it safe to send an 8-year-old to buy things. （ A） The man has never seen the woman before. （ B） The two speakers work fo
29、r the same company. （ C） The two speakers work on the same floor. （ D） The woman is interested in market research. （ A） The woman cant tolerate any noise. （ B） The man is looking for an apartment. （ C） The man has missed his appointment. （ D） The woman is going to take a train trip. （ A） Two hours a
30、nd a half. （ B） Three hours. （ C） Half an hour. （ D） An hour and a half. （ A） Mrs. Hill. （ B） Mr. Williams. （ C） Prof. Webster. （ D） Janet. （ A） Give Prof. Webster the key to Dons office. （ B） Return the mid-term exams to the students. （ C） Put the next assignment on the board. （ D） Pass on all the
31、news about Don. （ A） To teach students how to use English. （ B） To provide language learning opportunities. （ C） To offer job positions for graduating students. （ D） To help students prepare to enter institutions of higher learning. （ A） May 29th. （ B） June 29th. （ C） July 29th. （ D） August 29th. （
32、A） $2030. （ B） $2,300.00 （ C） $2,013.00 （ D） $2,035.00 （ A） Credit records. （ B） Application fee. （ C） Physical examination. （ D） High school transcripts. Section B Directions: In this section, you will hear 3 short passages. At the end of each passage, you will hear some questions. Both the passage
33、 and the questions will be spoken only once. After you hear a question, you must choose the best answer from the four choices marked A, B, C and D. （ A） He presented the bottle to an African tribe. （ B） He landed his plane in a remote desert. （ C） He threw the bottle out of the window. （ D） He conti
34、nued to watch a film. （ A） They believed it was a gift from the gods. （ B） They believed it was a warning from outside world. （ C） They believed it was a sign of misfortune. （ D） They believed it was a trouble-making property. （ A） What is delicious to some people may be poison to others. （ B） Argum
35、ents and conflicts arise easily even among primitive community. （ C） Modern civilization do not have influence on remote areas. （ D） The harmony of a peaceful society can be disturbed by a trivial incident. （ A） It remains as active as ever. （ B） It tends to be less active. （ C） It loses the ability
36、 to reason. （ D） It functions well in learning new things. （ A） Those in their 60s react more quickly than those in their 70s and 80s. （ B） Those who often use their minds may live a longer life than those who dont. （ C） Whether in their 60s, 70s or 80s, the minds do not have much difference. （ D） T
37、hose in their advanced age have more advantages in reasoning or knowledge. （ A） The old can do equally well compared with the young. （ B） The old may feel discouraged due to “loss of memory“. （ C） The old should slow their learning speed to catch the young. （ D） The old need not complain their memor
38、y is not as good as before. （ A） Synthetic fuel. （ B） Solar energy. （ C） Alcohol. （ D） Electricity. （ A） Air traffic conditions. （ B） Traffic jams on highways. （ C） Road conditions. （ D） New traffic rules. （ A） Go through a health check. （ B） Carry little luggage. （ C） Arrive early for boarding. （ D
39、） Undergo security checks. （ A） In a fast-food restaurant. （ B） At a shopping center. （ C） At a county fair. （ D） In a bakery. Section C Directions: In this section, you will hear a passage three times. When the passage is read for the first time, you should listen carefully for its general idea. Wh
40、en the passage is read for the second time, you are required to fill in the blanks numbered from 36 to 43 with the exact words you have just heard. For blanks numbered from 44 to 46 you are required to fill in the missing information. For these blanks, you can either use the exact words you have jus
41、t heard or write down the 36 We inherit our DNA from our parents. DNA is shuffled, recombined and【 B1】_from one generation to another. Each individual on this earth received 23【 B2】_of chromosomes from their parents(23 from dad and 23 from mom). Because DNA is【 B3】 _to a certain degree from one gene
42、ration to the next, it is possible to【 B4】 _family lines by【 B5】 _specific markers. The【 B6】 _of the Earth are more closely related than what it is generally thought. Today there are 6【 B7】 _people living on this planet. If we do some math, and we consider a generation to be about 25 years, 30 gener
43、ations ago, every individual living today would have over 1 billion【 B8】 _ancestors. The estimated world population for the year 1250 AD was 400 million people. This means that the number of actual ancestors for each individual is smaller than the number of possible ancestors and【 B9】 _.These common
44、 ancestors were able to transmit specific markers【 B10】 _. The Molecular Genealogy Research Group is very interested in people with known genealogies【 B11】 _.Being 18 and older and having at least a four-generation pedigree chart are the only two qualifications in order to take part in this study. 3
45、7 【 B1】 38 【 B2】 39 【 B3】 40 【 B4】 41 【 B5】 42 【 B6】 43 【 B7】 44 【 B8】 45 【 B9】 46 【 B10】 47 【 B11】 Section A Directions: In this section, there is a passage with ten blanks. You are required to select one word for each blank from a list of choices given in a word bank following the passage. Read th
46、e passage through carefully before making your choices. Each choice in the bank is identified by a letter. Please mark the corresponding letter for each item with a single line through the center. You may not use any of the words in the bank more than once. 47 Humans consume goods and services for m
47、any reasons: to nourish, clothe, and house ourselves, certainly. But we also consume as part of a social compact, since each community or social group has standards of dress, food,【 S1】 _, education, and entertainment that influence its patterns of consumption beyond physical【 S2】 _ At its best, con
48、sumption is a tool for human development-one that opens opportunities for a healthy and【 S3】 _life, with adequate nutrition, employment, mobility, and education. Poverty is【 S4】 _by a lack of consumption, and thus a lack of these opportunities. At the other extreme, wealth can-and often does-lead to
49、【 S5】_levels of material and nonmaterial consumption. In spite of its human benefits, consumption can lead to serious【 S6】 _on ecosystems. Consumption harms ecosystems directly【 S7】 _overharvesting of animals or plants, mining of soil nutrients, or other forms of biological depletion. Ecosystems suffer indirectly through pollution and wastes from agriculture,【 S8】_, and energy use, and also through fragmentation by roads and other i
